public class MyCircularQueue {
    //力扣 622. 设计循环队列
    //方法一浪费一个空间来实现
    public int[] elem;
    public int front;
    public int rear;

    public MyCircularQueue(int k) {
        elem = new int[k+1];
    }

    public boolean enQueue(int value) {
        if(isFull()){
            return false;
        }
        elem[rear]=value;
        rear=(rear+1)%elem.length;
        return true;
    }

    public boolean deQueue() {
        if(isEmpty()){
            return false;
        }
        front=(front+1)%elem.length;
        return true;
    }

    public int Front() {
        if (isEmpty()){
            return -1;
        }
        return elem[front];
    }

    public int Rear() {
        if (isEmpty()){
            return -1;
        }
        int index=rear==0?elem.length-1:rear-1;//不能使用(rear+1)%elem.length这样会使rear的值改变
        return elem[index];
    }

    public boolean isEmpty() {
        return front==rear;
    }

    public boolean isFull() {
        if((rear+1)%elem.length==front){
            return true;
        }
        return false;
    }
}
